The present invention relates to a novel methine dye compound, particularly a linking type methine dye compound having two chromophores linked thereto, and to a silver halide photographic material containing it.
Methine compounds have hitherto been used as a spectral sensitizing dye of silver halide photographic materials. With respect to technologies for enhancing a light absorbance of silver halide grains, those that have been known up to the date will be given below. In order to enhance the light absorbance per grain, it is necessary to increase an adsorption density of the sensitizing dye to the silver halide grains. The usual spectral sensitizing dyes are adsorbed in a monomolecular layer substantially in closest packaging, but cannot be adsorbed any more.
In order to solve this problem, there have been found some proposals. In Photographic Science and Engineering, Vol. 20, No. 3, page 97 (1976), P. B. Gilman, Jr., et al. adsorbed a cationic dye in a first layer and further adsorbed an anionic dye in a second layer by an electrostatic force. In U.S. Pat. No. 3,622,316, G. B. Bird, et al. underwent multi-layer adsorption of plural dyes on silver halide grains to achieve the sensitization by the contribution of a Forster model excitation energy transfer.
In JP-A-63-138341 and JP-A-64-84244, Sugimoto, et al. underwent spectral sensitization by energy transfer from a luminescent dye.
All of these technologies are concerned with trials to adsorb the dye in an amount of the saturated adsorption amount or more onto the silver halide grains. However, there were involved problems such that an effect for achieving high sensitivity is not so revealed and that the inherent desensitization increases.
On the other hand, binary dyes in which two or more non-conjugated dye chromophores are covalently linked are disclosed in U.S. Pat. Nos. 2,393,351, 2,425,772, 2,518,732, 2,521,944 and 2,592,196 and European Patent No. 565,083. However, these patents did not intend to enhance the light absorbance. As one positively intending to enhance the light absorbance, in U.S. Pat. Nos. 3,622,317 and 3,976,493, G. B. Bird, et al. proposed to adsorb a linking type sensitizing dye molecule having plural cyanine chromophores to increase the light absorbance, thereby attempting to achieve the sensitization by energy transfer. However, a remarkable effect for achieving high sensitivity is not obtained.
In JP-A-64-91134, Ukai, et al. propose to adsorb at least one substantially non-adsorbing dye containing at least two sulfo groups or carboxy groups on a spectral sensitizing dye capable of being adsorbed on a silver halide.
Further, in JP-A-6-27578, Vishwakarma, et al. undergo spectral sensitization using a binary dye in which an adsorbing cyanine dye and a non-adsorbing oxonol dye to silver halides are linked to each other. Moreover, in European Patent No. 887700A1, Parton, et al. undergo spectral sensitization using a binary dye in which an adsorbing cyanine dye and a non-adsorbing merocyanine dye are linked to each other using a specified linking group. However, in any of these cases, it may not be said that high sensitivity is thoroughly achieved by the contribution of energy transfer.
In addition, in JP-A-6-57235, Vishwakarma, et al. disclose a process of producing a binary dye in which a cyanine dye and a merocyanine dye are linked to each other. However, there are no working examples in which high sensitivity was achieved using this binary dye as a sensitizing dye for silver halide photographic material.
As described above, in any of the methods as described in the above-cited patents and literature references, sufficiently high sensitivity was not achieved. Accordingly, it has been considered necessary to perform further technical developments.
Accordingly, an object of the invention is to provide a novel methine-linked dye and a high-sensitivity silver halide photographic material containing it.
The foregoing object of the invention has been attained by the following means.
(1) A silver halide photographic material comprising a support and at least one photosensitive silver halide emulsion layer thereon, wherein the emulsion layer contains a compound represented by the following formula (1).
Dye1-"Parenopenst"L1"Parenopenst"Dye2)m1)m2.CIyxe2x80x83xe2x80x83Formula (1) 
In the formula, Dye1 represents a first chromophore; Dye2 represents a xanthene dye; L1 represents a linking group; m1 represents an integer of from 1 to 5; m2 represents an integer of from 1 to 5; CI represents an ion for neutralizing a charge; and y represents a number necessary for neutralizing the charge.
(2) The silver halide photographic material as set forth in (1) as above, wherein the xanthene dye is represented by the following formula (2). 
In the formula, X3 represents an oxygen atom or a sulfur atom; R11 represents any one of xe2x80x94OM, xe2x80x94SM, and xe2x80x94NR2OR21; R12 represents any one of xe2x95x90O, xe2x95x90S, and xe2x95x90+NR22R23; M represents a proton or a cation; R20 to R23 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group; R20 and R21, or R22 and R23 may be linked to each other to form a ring; R13 to R19 each independently represents a hydrogen atom or a substituent; and in R11 to R19, the adjacent substituents may be linked to each other to form a ring.
(3) The silver halide photographic material as set forth in (2) as above, wherein in the formula (2), X3 represents an oxygen atom.
(4) The silver halide photographic material as set forth in (2) or (3) as above, wherein in the formula (2), R13 represents an unsubstituted or substituted aryl group.
(5) The silver halide photographic material as set forth in (4) as above, wherein in the formula (2), R13 represents a phenyl group substituted with any one of a carboxyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfo group, a halogen atom, an amino group, a hydroxyl group, an alkyl group, and an alkoxy group.
(6) The silver halide photographic material as set forth in any one of (2) to (5) as above, wherein in the formula (2), R1, represents any one of xe2x80x94OM and xe2x80x94NR2OR21; and R12 represents any one of xe2x95x90O and xe2x95x90+NR22R23.
(7) The silver halide photographic material as set forth in any one of (2) to (6) as above, wherein in the formula (2), R11 represents xe2x80x94OM; R12 represents xe2x95x90O; and all of R14, R15, R17, and R18 represent a halogen atom.
(8) The silver halide photographic material as set forth in any one of (2) to (6) as above, wherein in the formula (2), R1, represents xe2x80x94NR2OR21; R12 represents xe2x95x90+NR22R23; and R14, R15, R17, and R18 each independently represents a hydrogen atom or an alkyl group.
(9) The silver halide photographic material as set forth in any one of (1) to (8) as above, wherein in the compound represented by the formula (1), Dye1 represents any one of a cyanine chromophore, a merocyanine chromophore, and an oxonol chromophore.
(10) The silver halide photographic material as set forth in any one of (1) to (9) as above, wherein in the compound represented by the formula (1), Dye1 represents a cyanine chromophore.
(11) The silver halide photographic material as set forth in any one of (1) to (10) as above, wherein in the compound represented by the formula (1), L1 represents -G1-(A1-G2)t1-, wherein G1 and G2 each independently represents an alkylene group, an alkenylene group, or an arylene group; A1 represents anyone of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94NR3xe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94CONR4xe2x80x94, and xe2x80x94SO2NR5xe2x80x94, regardless of the left or right direction; R3 to R5 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group; and t1 represents an integer of from 1 to 10.
(12) The silver halide photographic material as set forth in any one of (1) to (11) as above, wherein the compound represented by the formula (1) is represented by the following formula (3). 
In the formula, X3 and R11 to R19 are synonymous with those in the formula (2); G1, G2, A1, and t1 are synonymous with those in (11); X1 and X2 each independently represents xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR6xe2x80x94, or xe2x80x94CR7R8xe2x80x94; R6 to R8 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group; R1 and R2 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group; M1 to M3 each independently represents a methine group; n1 represents an integer of from 0 to 3; V1 and V2 each represents a substituent; n2 and n3 each represents an integer of from 0 to 4; when each of n2 and n3 is 2 or more, V1s"" and V2s"" may be respectively the same or different, or may be linked to each other to form a ring; CI represents an ion for neutralizing a charge; and y represents a number necessary for neutralizing the charge, provided that G1 is linked to Dye1 at R1 or V1, and G2 is linked to Dye2 at any one of R11 to R19.
(13) The silver halide photographic material as set forth in (11) or (12) as above, wherein in the compound represented by the formula (1) or (3), G1 and G2 each represents an alkylene group.
(14) The silver halide photographic material as set forth in any one of (11) to (13) as above, wherein in the compound represented by the formula (1) or (3), A1 represents xe2x80x94Oxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94COOxe2x80x94, or xe2x80x94CONR4xe2x80x94.
(15) The silver halide photographic material as set forth in any one of (12) to (14) as above, wherein in the compound represented by the formula (3), X1 and X2 each represents xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94.
(16) The silver halide photographic material as set forth in any one of (12) to (15) as above, wherein in the compound represented by the formula (3), n1 is 0 or 1.
(17) The silver halide photographic material as set forth in (16) as above, wherein in the compound represented by the formula (3), n1 is 1.
(18) The silver halide photographic material as set forth in (17) as above, wherein in the compound represented by the formula (3), n1 is 1; and X1 and X2 each represents xe2x80x94Oxe2x80x94.
(19) The silver halide photographic material as set forth in any one of (12) to (18) as above, wherein in the compound represented by the formula (3), G1 is linked to R1.
(20) The silver halide photographic material as set forth in any one of (12) to (19) as above, wherein in the compound represented by the formula (3), G2 is linked to R13.
(21) The silver halide photographic material as set forth in any one of (1) to (20) as above, wherein in the compound represented by the formula (1) or (3), an adsorptivity to silver halide grains is in the relationship of Dye1 greater than Dye2.
(22) The silver halide photographic material as set forth in any one of (1) to (21) as above, wherein in the silver halide photographic emulsion, the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1, and Dye2 not adsorbed on the silver halide grains causes electron trnasfer or energy transfer to Dye1 upon light excitation.
(23) The silver halide photographic material as set forth in any one of (1) to (22) as above, wherein in the silver halide photographic emulsion, the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1 to form J association.
(24) The silver halide photographic material as set forth in any one of (1) to (23), wherein in the silver halide photographic emulsion, when the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1, Dye2 keeps a monomer state in an adsorbing spectral manner.
(25) The silver halide photographic material as set forth in any one of (1) to (24), wherein the silver halide photographic emulsion containing the compound represented by the formula (1) or (3) as set forth in any one of (1) to (24) as above is an emulsion in which tabular grains having an aspect ratio of 2 or more account for 50% (area) or more of the whole of the silver halide grains.
(26) The silver halide photographic material as set forth in any one of (1) to (25), wherein the silver halide photographic emulsion containing the compound represented by the formula (1) or (3) as set forth in any one of (1) to (25) as above is subjected to selenium sensitization.
(27) A dyes represented by the formula (3) as set forth in any one of (12) to (20) as above.
The compound represented by the formula (1) according to the invention will be described below in detail.
Incidentally, when the compound of the invention has an alkyl group, an alkylene group, an alkenyl group, or an alkenylene group, these groups may be linear or branched and may be substituted or unsubstituted, unless otherwise indicated.
Further, when the compound of the invention has a cycloalkyl group, an aryl group, a heterocyclic group, a cycloalkenylene group, an arylene group, or a heterylene group, these groups may be monocyclic or fused and may be substituted or unsubstituted, unless otherwise indicated.
In the invention, in the case where a specified moiety is called xe2x80x9cgroupxe2x80x9d, it is meant that the instant moiety may be unsubstituted itself or may be substituted with one or more (up to an allowable maximum number) substituents.
For example, the term xe2x80x9calkyl groupxe2x80x9d means a substituted or unsubstituted alkyl group. Further, the substituent which can be used in the compound of the invention include any substituents regardless of the presence or absence of substitution. For example, is enumerated the following group of substituents represented by W.
As the substituent represented by W, any substituents can be used without particular limitations. Examples include a halogen atom, an alkyl group [(including a cycloalkyl group, a bicycloalkyl group, and a tricycloalkyl group) and also including an alkenyl group (including a cycloalkenyl group and a bicycloalkenyl group) and an alkynyl group], an aryl group, a heterocyclic group (may be called a hetero ring group), a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group, an aryloxy group, a silyloxy group, a heterocyclic oxy group, an acyloxy group, a carbamoyloxy group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an amino group (including an anilino group), an ammonio group, an acylamino group, an aminocarbonylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfamoylamino group, an alkyl- or arylsulfonylamino group, a mercapto group, an alkylthio group, an arylthio group, a heterocyclic thio group, a sulfamoyl group, a sulfo group, an alkyl- or arylsulfinyl group, an alkyl- or arylsulfonyl group, an acyl group, an aryloxycarbonyl group, an alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, a phosphinyl group, a phosphinyloxy group, a phosphinylamino group, a phospho group, a silyl group, a hydrazino group, a ureido group, and other known substituents.
More specifically, W represents a halogen atom (such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom), an alkyl group [[representing a linear, branched or cyclic, substituted or unsubstituted alkyl group, inclusive of an alkyl group (preferably an alkyl group having from 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, t-butyl, n-octyl, eucosyl, 2-chloroethyl, 2-cyanoethyl, and 2-ethylhexyl), a cycloalkyl group (preferably a substituted or unsubstituted cycloalkyl group having from 3 to 30 carbon atoms, such as cyclohexyl, cyclopentyl, and 4-n-dodecylcyclohexyl), a bicycloalkyl group (preferably a substituted or unsubstituted bicycloalkyl group having from to 30 carbon atoms, i.e., a monovalent group in which one hydrogen atom has been eliminated from a bicycloalkane having from 5 to 30 carbon atoms, such as bicyclo[1,2,2]heptan-2-yl and bicyclo[2,2,2]octan-3-yl), and a tricyclo structure having a more ring; and the alkyl group in the following substituents (for example, an alkyl group of an alkylthio group) represents an alkyl group having such a concept and further includes an alkenyl group and an alkynyl group], an alkenyl group [representing a linear, branched or cyclic, substituted or unsubstituted alkenyl group, inclusive of an alkenyl group (preferably a substituted or unsubstituted alkenyl group having from 2 to 30 carbon atoms, such as vinyl, allyl, prenyl, gelanyl, and oleyl), a cycloalkenyl group (preferably a substituted or unsubstituted cycloalkenyl group having from 3 to 30 carbon atoms, i.e., a monovalent group in which one hydrogen atom has been eliminated from a cycloalkene having from 3 to 30 carbon atoms, such as 2-cyclopenten-1-yl and 2-cyclohexen-1-yl), and a bicycloalkenyl group (a substituted or unsubstituted bicycloalkenyl group, and preferably a substituted or unsubstituted bicycloalkenyl group having from 5 to 30 carbon atoms, i.e., a monovalent group in which one hydrogen atom has been eliminated from a bicycloalkene having one double bond, such as bicyclo-[2,2,1]hept-2-en-1-yl and bicyclo[2,2,2]oct-2-en-4-yl)], and an alkynyl group (preferably a substituted or unsubstituted alkynyl group having from 2 to 30 carbon atoms, such as ethynyl, propargyl, and trimethylsilylethynyl)], an aryl group (preferably a substituted or unsubstituted aryl group having from 6 to 30 carbon atoms, such as phenyl, p-tolyl, naphthyl, m-chlorophenyl, and o-hexadecanoylaminophenyl), a heterocyclic group (preferably a monovalent group in which one hydrogen atom has been eliminated from a 5- or 6-membered, substituted or unsubstituted aromatic or non-aromatic heterocyclic compound, and more preferably a 5- or 6-membered aromatic heterocyclic group having from 3 to 30 carbon atoms, such as 2-furyl, 2-thienyl, 2-pyrimidinyl, 2-benzothiazoyl, and cationic heterocyclic groups (e.g., 1-methyl-2-pyridinio, 1-methyl-2-quinolinio)), a cyano group, a hydroxyl group, a nitro group, a carboxyl group, an alkoxy group (preferably a substituted or unsubstituted alkoxy group having from 1 to 30 carbon atoms, such as methoxy, ethoxy, isopropoxy, t-butoxy, n-octyloxy, and 2-methoxyethoxy), an aryloxy group (preferably a substituted or unsubstituted aryloxy group having from 6 to 30 carbon atoms, such as phenoxy, 2-methylphenoxy, 4-t-butylphenoxy, and 3-nitrophenoxy, 2-tetradecanoylaminophenoxy), a silyloxy group (preferably a silyloxy group having from 3 to 20 carbon atoms, such as trimethylsilyloxy and t-butyldimethylsilyloxy), a heterocyclic oxy group (preferably a substituted or unsubstituted heterocyclic oxy group having from 2 to 30 carbon atoms, such as 1-phenyltetrazol-5-oxy and 2-tetrahydropyranyloxy), an acyloxy group (preferably a formyloxy group, a substituted or unsubstituted alkylcarbonyloxy group having from 2 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonyloxy group, such as formyloxy, acetyloxy, pivaloyloxy, stearoyloxy, benzoyloxy, and p-methoxyphenylcarbonyloxy), a carbamoyloxy group (preferably a substituted or unsubstituted having from 1 to 30 carbon atoms, such as N,N-dimethylcarbamoyloxy, N,N-diethylcarbamoyloxy, morpholinocarbonyloxy, N,N-di-n-octylaminocarbonyloxy, and N-n-octylcarbamoyloxy) an alkoxycarbonyloxy group (preferably a substituted or unsubstituted alkoxycarbonyloxy group having from 2 to 30 carbon atoms, such as methoxycarbonyloxy, ethoxycarbonyloxy, t-butoxycarbonyloxy, and n-octylcarbonyloxy), an aryloxycarbonyloxy group (preferably a substituted or unsubstituted aryloxycarbonyloxy group having from 7 to 30 carbon atoms, such as phenoxycarbonyloxy, p-methoxyphenoxycarbonyloxy, and p-n-hexadecyloxyphenoxycarbonyloxy), an amino group (preferably an amino group, a substituted or unsubstituted alkyamino group having from 1 to 30 carbon atoms, and a substituted or unsubstituted anilino group having from 6 to 30 carbon atoms, such as amino, methylamino, dimethylamino, anilino, N-methyl-anilino, and dipehnylamino), an ammonio group (preferably an ammonio group and an ammonio group substituted with an alkyl, aryl or heterocyclic group having from 1 to 30 carbon atoms, such as trimethylammonio, triethylammonio, and dipehnylmethylammonio), an acylamino group (preferably a formylamino group, a substituted or unsubstituted alkylcarbonylamino group having from 1 to 30 carbon atoms, and a substituted or unsubstituted arylcarbonylamino group having from 6 to 30 carbon atoms, such as formylamino, acetylamino, pivaloylamino, lauroylamino, benzoylamino, and 3,4,5-tri-n-octyloxyphenylcarbonylamino), an aminocarbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having from 1 to 30 carbon atoms, such as carbamoylamino, N,N-dimethylaminocarbonylamino, N,N-diethylaminocarbonylamino, and morpholinocarbonylamino), an alkoxycarbonylamino group (preferably a substituted or unsubstituted alkoxycarbonylamino group having from 2 to 30 carbon atoms, such as methoxycarbonylamino, ethoxycarbonylamino, t-butoxycarbonylamino, n-octadecyloxycarbonylamino, and N-methyl-methoxycarbonylamino), an aryloxycarbonylamino group (preferably a substituted or unsubstituted aryloxycarbonylamino group having from 7 to 30 carbon atoms, such as phenoxycarbonylamino, p-chlorophenoxycarbonylamino, and m-n-octyloxyphenoxycarbonylamino), a sulfamoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having from 0 to 30 carbon atoms, such as sulfamoylamino, N,N-dimethylaminosulfonylamino and N-n-octylaminosulfonylamino), an alkyl- or arylsulfonylamino group (preferably a substituted or unsubstituted alkylsulfonylamino group having from 1 to 30 carbon atoms and a substituted or unsubstituted arylsulfonylamino group having from 6 to 30 carbon atoms, such as methylsulfonylamino, butylsulfonylamino, phenylsulfonylamino, 2,3,5-trichlorophenylsulfonylamino, and p-methylphenylsulfonylamino), a mercapto group, an alkylthio group (preferably a substituted or unsubstituted alkylthio group having from 1 to 30 carbon atoms, such as methylthio, ethylthio, and n-hexadecylthio), an arylthio group (preferably a substituted or unsubstituted arylthio group having from 6 to 30 carbon atoms, such as phenylthio, p-chlorophenylthio, and m-methoxyphenylthio), a heterocyclic thio group (preferably a substituted or unsubstituted heterocyclic thio group having from 2 to 30 carbon atoms, such as 2-benzothiazolylthio and 1-phenyltetrazol-5-ylthio), a sulfamoyl group (preferably a substituted or unsubstituted sulfamoyl group having from 0 to 30 carbon atoms, such as N-ethylsulfamoyl, N-(3-dodecyloxypropyl)sulfamoyl, N,N-dimethylsulfamoyl, N-acetylsulfamoyl, N-benzoylsulfamoyl, and N-(N-phenylcarbamoyl)sulfamoyl), a sulfo group, an alkyl- or arylsulfinyl group (preferably a substituted or unsubstituted alkylsulfinyl group having from 1 to 30 carbon atoms and a substituted or unsubstituted arylsulfinyl group having from 6 to 30 carbon atoms, such as methylsulfinyl, ethylsulfinyl, phenylsulfinyl, and p-methylphenylsulfinyl), an alkyl- or arylsulfonyl group (preferably a substituted or unsubstituted alkylsulfonyl group having from 1 to 30 carbon atoms and a substituted or unsubstituted arylsulfonyl group having from 6 to 30 carbon atoms, such as methylsulfonyl, ethylsulfonyl, phenylsulfonyl, and p-methylphenylsulfonyl), an acyl group (preferably a formyl group, a substituted or unsubstituted alkylcarbonyl group having from 2 to 30 carbon atoms, a substituted or unsubstituted arylcarbonyl group having from 7 to 30 carbon atoms, and a substituted or unsubstituted heterocyclic carbonyl group having from 4 to 30 carbon atoms, which is bound to a carbonyl group at a carbon atom, such as acetyl, pivaloyl, 2-chloroacetyl, stearoyl, benzoyl, p-n-octyloxyphenylcarbonyl, 2-pyridylcarbonyl, and 2-furylcarbonyl), an aryloxycarbonyl group (preferably a substituted or unsubstituted aryloxycarbonyl group having from 7 to 30 carbon atoms, such as phenoxycarbonyl, o-chlorophenoxycarbonyl, m-nitrophenoxycarbonyl, and p-t-butylphenoxycarbonyl), an alkoxycarbonyl group (preferably a substituted or unsubstituted alkoxycarbonyl group having from 2 to 30 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, t-butoxycarbonyl, and n-octadecyloxycarbonyl), a carbamoyl group (preferably a substituted or unsubstituted carbamoyl group having from 1 to 30 carbon atoms, such as carbamoyl, N-methylcarbamoyl, N,N-dimethylcarbamoyl, N,N-di-n-octylcarbamoyl, and N-(methylsulfonyl)carbamoyl, an aryl or heterocyclic azo group (preferably a substituted or unsubstituted aryl azo group having from 6 to 30 carbon atoms and a substituted or unsubstituted heterocyclic azo group having from 3 to 30 carbon atoms, such as phenylazo, p-chlorophenylazo, and 5-ethylthio-1,3,4-thiazol-2-ylazo), an imido group (preferably N-succinimido and N-phthalimido), a phosphino group (preferably a substituted or unsubstituted phosphino group having from 2 to 30 carbon atoms, such as dimethylphosphino, diphenylphosphino, and methylphenoxyphosphino), a phosphinyl group (preferably a substituted or unsubstituted phosphinyl group having from 2 to 30 carbon atoms, such as phosphinyl, dioctyloxyphosphinyl, and diethoxyphosphinyl), a phosphinyloxy group (preferably a substituted or unsubstituted phosphinyloxy group having from 2 to 30 carbon atoms, such as diphenoxyphosphinyloxy and dioctyloxyphosphinyloxy), a phosphinylamino group (preferably a substituted or unsubstituted phosphinylamino group having from 2 to 30 carbon atoms, such as dimethoxyphosphinylamino and dimethylaminophosphinylamino), a phospho group, a silyl group (preferably a substituted or unsubstituted silyl group having from 3 to 30 carbon atoms, such as trimethylsilyl, t-butyldimethylsilyl, and phenyldimethylsilyl), a hydrazino group (preferably a substituted or unsubstituted hydrazino group having from 0 to 30 carbon atoms, such as trimethylhydrazino), and a ureido group (preferably a substituted or unsubstituted ureido group having from 0 to 30 carbon atoms, such as N-dimethylureido).
Also, W may take a structure comprising rings fused with each other. The ring is an aromatic or non-aromatic hydrocarbon ring or a heterocyclic ring, or may form a polycyclic fused ring formed by a combination of these rings. Examples of the ring include a benzene ring, a naphthalene ring, an anthracene ring, a phenanthrene ring, a fluorene ring, a triphenylene ring, a naphthacene ring, a biphenyl ring, a pyrrole ring, a furan ring, a thiophene ring, an imidazole ring, an oxazole ring, a thiazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, an indolizine ring, an indole ring, a benzofuran ring, a benzothiophene ring, an isobenzofuran ring, a quinolizine ring, a quinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinoxazoline ring, an isoquinoline ring, a carbazole ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a thianthrene ring, a chromene ring, a xanthene ring, a phenoxathiine ring, a phenothiazine ring, and a phenazine ring.
Among the substituents represented by W, those having a hydrogen atom or atoms may be further substituted with the foregoing substituent(s) after eliminating the hydrogen atom or atoms. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Specific examples include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.
In the formula (1), L1 represents a linking group and may be any linking group. Preferably, L1 represents a linking group having from 0 to 100 carbon atoms, and preferably from 1 to 20 carbon atoms, which is constituted of one or more of an alkylene group (preferably an alkylene group having from 1 to 20 carbon atoms, such as methylene, ethylene, propylene, butylene, pentylene, hexylene, and octylene), an arylene group (preferably an arylene group having from 6 to 26 carbon atoms, such as phenylene and naphthylene), an alkenylene group (preferably an alkenylene group having from 2 to 20 carbon atoms, such as ethenylene and propenylene), an alkynylene group (preferably an alkynylene group having from 2 to 20 carbon atoms, such as ethynylene and propynylene), an amide group, an ester group, a sulfonamide group, a sulfonic acid ester group, a ureido group, a sulfonyl group, a sulfinyl group, a thioether group, an ether group, a carbonyl group, xe2x80x94NR51xe2x80x94 (wherein R51 represents a hydrogen atom or a monovalent substituent, and as the substituent, W is preferably enumerated), and a heterylene group (preferably a heterylene group having from 1 to 26 carbon atoms, such as a 6-chloro-1,3,5-triazyl-2,4-diyl group, a pyrimidine-2,4-diyl group, and a quinoxaline-2,3-diyl group).
More preferably, L1 is represented by -G1-(A1-G2-)t1.
A1 represents any one of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94NR3xe2x80x94, xe2x80x94COOxe2x80x94, xe2x80x94CONR4xe2x80x94, and xe2x80x94SO2NR5xe2x80x94, regardless of the left or right direction; R3 to R5 each independently represents a hydrogen atom, an alkyl group [preferably an unsubstituted alkyl group having from 1 to 18 carbon atoms, more preferably from 1 to 7 carbon atoms, and most preferably from 1 to 4 carbon atoms (such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, 2-ethylhexyl, dodecyl, and octadecyl) and a substituted alkyl group having from 1 to 18 carbon atoms, more preferably from 1 to 7 carbon atoms, and most preferably from 1 to 4 carbon atoms {as the substituent, the alkyl group having W substituted thereon is enumerated, preferably an aralkyl group (such as benzyl and 2-phenylethyl), a hydroxyalkyl group (such as 2-hydroxyethyl, 3-hydroxypropyl, and 6-hydroxyhexyl), a carboxyalkyl group (such as 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, carboxymethyl, and 5-carboxypentyl), an alkoxyalkyl group (such as 2-methoxyethyl and 2-(2-methoxyethoxy)ethyl), an aryloxyalkyl group (such as 2-phenoxyethyl and 2-(1-naphthoxy) ethyl), an alkoxycarbonylalkyl group (such as ethoxycarbonylmethyl and 2-benzyloxycarbonylethyl), an aryloxycarbonylalkyl group (such as 3-phenoxycarbonylpropyl), an acyloxyalkyl group (such as 2-acetyloxyethyl), an acylalkyl group (such as 2-acetylethyl), a carbamoylalkyl group (such as 2-morpholinocarbonylethyl), a sulfamoylalkyl group (such as N,N-dimethylsulfamoylmethyl), a sulfoalkyl group (such as 2-sulfobenzyl, 3-sulfo-3-phenylpropyl, 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, 2-[3-sulfopropoxy]ethyl, 2-hydroxy-3-sulfopropyl, and 3-sulfopropoxyethoxyethyl), a sulfatoalkyl group (such as 2-sulfatoethyl, 3-sulfatopropyl, and 4-sulfatobutyl), a hetero ring-substituted alkyl group (such as 2-(pyrrolidin-2-on-1-yl)ethyl and tetrahydrofurfuryl), an alkylsulfonylcarbamoylalkyl group (such as methanesulfonylcarbamoylmethyl), an acylcarbamoylalkyl group (such as acetylcarbamoylmethyl), an acylsulfamoylalkyl group (such as acetylsulfamoylmethyl), an alkylsulfonylsulfamoylalkyl group (such as methanesulfonylsulfamoylmethyl), and a halogen-substituted alkyl group (such as 2-chloroethyl and 2,2,2-trifluoroethyl)})], an alkenyl group (preferably an alkenyl group having from 2 to 20 carbon atoms, such as vinyl, allyl, 3-butenyl, and oleyl; and an alkenyl group having W substituted thereon, such as a sulfoalkenyl group (e.g., 3-sulfo-2-propenyl)), an aryl group (preferably a substituted or unsubstituted aryl group having from 6 to 20 carbon atoms, more preferably from 6 to 10 carbon atoms, and most preferably from 6 to 8 carbon atoms (as the substituent, W is enumerated; such as phenyl, 1-naphthyl, 2-naphthyl, p-methoxyphenyl, p-methylphenyl, and p-chlorophenyl), or a heterocyclic group (preferably a substituted or unsubstituted heterocyclic group having from 1 to 20 carbon atoms, more preferably from 3 to 10 carbon atoms, and most preferably from 4 to 8 carbon atoms (as the substituent, W is enumerated; such as 2-furyl, 2-thienyl, 2-pyridyl, 3-pyrazolyl, 3-isoxazoyl, 3-isothiazoyl, 2-imidazoyl, 2-oxazolyl, 2-thiazolyl, 2-pyridazyl, 2-pyrimidyl, 3-pyrazyl, 2-(1,3,5-triazolyl), 3-(1,24-triazolyl), 5-tetrazolyl, 5-methyl-2-thienyl, and 4-methoxy-2-pyridyl).
R3 preferably represents a hydrogen atom or an alkyl group, and more preferably an alkyl group.
Preferably, R4 and R5 each represents a hydrogen atom or an alkyl group, and more preferably a hydrogen atom.
A1 preferably represents xe2x80x94Oxe2x80x94, xe2x80x94SO2xe2x80x94, xe2x80x94COOxe2x80x94, or xe2x80x94CONR4xe2x80x94, and more preferably xe2x80x94Oxe2x80x94 or xe2x80x94CONR4xe2x80x94.
G1 and G2 each independently represents an alkylene group, an alkenylene group, or an arylene group (preferred examples are the same as in L1), and may be substituted with W. Preferably, G1 and G2 each presents an alkylene group, and more preferably an unsubstituted linear alkylene group having from 1 to 8 carbon atoms.
t1 represents an integer of from 1 to 10, preferably an integer of from 1 to 4, and more preferably an integer of from 1 to 3. When t1 is 2 or more, plural A1s"" and G2s"" may be respectively the same or different.
When t1 is 1, A1 preferably represents any one of xe2x80x94COOxe2x80x94, xe2x80x94CONR4xe2x80x94, and xe2x80x94SO2NR5xe2x80x94, more preferably xe2x80x94COOxe2x80x94 or xe2x80x94CONR4xe2x80x94, and most preferably xe2x80x94CONR4xe2x80x94.
When t1 is 2 or more, at least one of A1s"" preferably represents any one of xe2x80x94COOxe2x80x94, xe2x80x94CONR4xe2x80x94, and xe2x80x94SO2NR5xe2x80x94, more preferably xe2x80x94COOxe2x80x94 or xe2x80x94CONR4xe2x80x94, and most preferably xe2x80x94CONR4xe2x80x94.
Further, the rest of A1s"" more preferably represents any one of xe2x80x94COOxe2x80x94, xe2x80x94CONR4xe2x80x94, xe2x80x94SO2NR5xe2x80x94, xe2x80x94Oxe2x80x94, and xe2x80x94SO2xe2x80x94, and most preferably xe2x80x94Oxe2x80x94 or xe2x80x94CONR4xe2x80x94.
m1 represents an integer of from 1 to 5, preferably 1 or 2, and more preferably 1; and m2 represents an integer of from 1 to 5, preferably 1 or 2, and more preferably 1. Most preferably, m1 and m2 are each 1.
Dye1 represents a first chromophore. Any chromophore may be used as the chromophore represented by Dye1. Examples include cyanine dyes, styryly dyes, hemicyanine dyes, merocyanine dyes, trinuclear merocyanine dyes, tetranuclear merocyanine dyes, rhodacyanine dyes, complex cyanine dyes, complex merocyanine dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squarylium dyes, croconium dyes, azamethine dyes, coumarin dyes, arylidene dyes, anthraquinone dyes, triphenylmethane dyes, azo dyes, azomethine dyes, spiro compounds, metallocene dyes, fluorenone dyes, fulgide dyes, perylene dyes, phenazine dyes, phenothiazine dyes, quinone dyes, indigo dyes, diphenylmethane dyes, polyene dyes, acridine dyes, acridinone dyes, diphenylamine dyes, quinacridone dyes, quinophthalone dyes, phenoxazine dyes, phthaloperylene dyes, porphyrin dyes, chlorophile dyes, phthalocyanine dyes, metal complex dyes, and xanthene dyes.
Preferably, are enumerated polymethine chromophores such as cyanine dyes, styryl dyes, hemicyanine dyes, merocyanine dyes, trinuclear merocyanine dyes, tetranuclear merocyanine dyes, rhodacyanine dyes, complex cyanine dyes, complex merocyanide dyes, allopolar dyes, oxonol dyes, hemioxonol dyes, squarylium dyes, croconium dyes, azamethine dyes, and oxonol dyes.
The details of these dyes are described in, for example, F. M. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John Wiley and Sons, Yew York, London (1964) and D. M. Sturmer, Heterocyclic Compounds-Special Topics in Heterocyclic Chemistry, Chapter 18, Section 14, pages 482 to 515. As the formulae of preferred dyes, are enumerated the formulae given at pages 32 to 36 of U.S. Pat. No. 5,994,051 and those given at pages 30 to 34 of U.S. Pat. No. 5,747,236. Further, as the formulae of preferred cyanine dyes, merocyanine dyes and rhodacyanine dyes, are enumerated the formulae (XI), (XII) and (XIII) given in columns 21 to 22 of U.S. Pat. No. 5,340,694 (however, the number of each of n12, n15, n17 and n18 is not limited, but is an integer of 0 or more (preferably 4 or less)).
Preferably, Dye1 represents any one of a cyanine chromophore, a merocyanine chromophore, and an oxonol chromophore, more preferably any one of a cyanine chromophore and a merocyanine chromophore, and most preferably a cyanine chromophore.
The cyanine chromophore is preferably a chromophore represented by the following formula (4). 
In the formula, Za1 and Za2 each represents an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocyclic ring, which may be further fused with a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, or a thiophene ring.
Ra1 and Ra2 each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group (preferred examples are the same as in R3 to R5), preferably a hydrogen atom, an alkyl group, or a sulfoalkyl group, and more preferably an alkyl group or a sulfoalkyl group.
Ma1 to Ma7 each represents a methine group, which may have a substituent. As the substituent, any of those enumerated above for W can be used. Preferably, examples of the substituent include an alkyl group having from 1 to 20 carbon atoms (such as methyl, ethyl, and isopropyl), a halogen atom (such as chlorine, bromine, iodine, and fluorine), a nitro group, an alkoxy group having from 1 to 20 carbon atoms (such as methoxy and ethoxy), an aryl group having from 6 to 26 carbon atoms (such as phenyl and 2-naphthyl), a heterocyclic group having from 0 to 20 carbon atoms (such as 2-pyridyl and 3-pyridyl), an aryloxy group having from 6 to 20 carbon atoms (such as phenoxy, 1-naphthoxy, and 2-naphthoxy), an acylamino group having from 1 to 20 carbon atoms (such as acetylamino and benzoylamino), a carbamoyl group having from 1 to 20 carbon atoms (such as N,N-dimethylcarbamoyl), a sulfo group, a hydroxyl group, a carboxy group, an alkylthio group having from 1 to 20 carbon atoms (such as methylthio), and a cyano group. The methine group may be taken together with other methine group to form a ring, or may be taken together with an auxochrome to form a ring. Preferably, the methine group is an unsubstituted, ethyl group-substituted, or methyl group-substituted methine group.
na1 and na2 are each 0 or 1, and preferably 0. ka1 represents an integer of from 0 to 3, preferably an integer of from 0 to 2, and more preferably 0 or 1. When ka1 is 2 or more, Ma3s"" and Ma4s"" may be respectively the same or different.
CI represents an ion for neutralizing a charge; and y represents a number necessary for neutralizing the charge.
The merocyanine chromophore is preferably a chromophore represented by the following formula (5). 
In the formula, Za3 represents an atomic group forming a 5-membered or 6-membered nitrogen-containing heterocyclic ring, which may be further fused with a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, or a thiophene ring. Za4 represents an atomic group forming an acid nucleus. Ra3 represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group (preferred examples are the same as in Ra1 and Ra2). Ma8 to Ma11 each represents a methine group (preferred examples are the same as in Ma1 to Ma7). na3 is 0 or 1. ka2 represents an integer of from 0 to 3, preferably an integer of from 0 to 2, and more preferably 1 or 2.
When ka2 is 2 or more, Ma10s"" and Ma11s"" maybe respectively the same or different.
CI represents an ion for neutralizing a charge; and y represents a number necessary for neutralizing the charge.
The oxonol chromophore is preferably a chromophore represented by the following formula (6). 
In the formula, Za5 and Za6 each represents an atomic group forming an acid nucleus. Ma12 to Ma14 each represents a methine group (preferred examples are the same as in Ma1 to Ma7). ka3 represents an integer of from 0 to 3, and preferably an integer of from 0 to 2. When ka3 is 2 or more, Ma12s"" and Ma13s"" may be respectively the same or different.
CI represents an ion for neutralizing a charge; and represents a number necessary for neutralizing the charge.
Examples of Za1, Za2 and Za3 include an oxazole nucleus having from 3 to 25 carbon atoms (such as 2-3-methyloxazolyl, 2-3-ethyloxazolyl, 2-3,4-diethyloxazolyl, 2-3-methylbenzoxazolyl, 2-3-ethylbenzoxazolyl, 2-3-sulfoethylbenzoxazolyl, 2-3-sulfopropylbenzoxazolyl, 2-3-methylthioethylbenzoxazolyl, 2-3-methoxyethylbenzoxazolyl, 2-3-sulfobutylbenzoxazolyl, 2-3-methyl-xcex2-naphthoxazolyl, 2-3-methyl-xcex1-naphthoxazolyl, 2-3-sulfopropyl-∘-naphthoxazolyl, 2-3-sulfopropyl-xcex3-naphthoxazolyl, 2-3-(3-naphthoxyethyl)benzoxazolyl, 2-3,5-dimethylbenzoxazolyl, 2-6-chloro-3-methylbenzoxazolyl, 2-5-bromo-3-methylbenzoxazolyl, 2-3-ethyl-5-methoxybenzoxazolyl, 2-5-phenyl-3-sulfopropylbenzoxazolyl, 2-5-(4-bromophenyl)-3-sulfobutylbenzoxazolyl, and 2-3-dimethyl-5,6-dimethylthiobenzoxazolyl), a thiazole nucleus having from 3 to 25 carbon atoms (such as 2-3-methylthiazolyl, 2-3-ethylthiazolyl, 2-3-sulfopropylthiazolyl, 2-3-sulfobutylthiazolyl, 2-3,4-dimethylthiazolyl, 2-3,4,4-trimethylthiazolyl, 2-3-carboxyethylthiazolyl, 2-3-methylbenzothiazolyl, 2-3-ethylbenzothiazolyl, 2-3-butylbenzothiazolyl, 2-3-sulfopropylbenzothiazolyl, 2-3-sulfobutylbenzothiazolyl, 2-3-methyl-xcex2-naphthothiazolyl, 2-3-sulfopropyl-xcex3-naphthothiazolyl, 2-3-(1-naphthoxyethyl)benzothiazolyl, 2-3,5-dimethylbenzothiazolyl, 2-6-chloro-3-methylbenzothiazolyl, 2-6-iodo-3-ethylbenzothiazolyl, 2-5-bromo-3-methylbenzothiazolyl, 2-3-ethyl-5-methoxybenzothiazolyl, 2-5-phenyl-3-sulfopropylbenzothiazolyl, 2-5-(4-bromophenyl)-3-sulfobutylbenzothiazolyl, and 2-3-dimethyl-5,6-dimethylthiobenzothiazolyl), an imidazole nucleus having from 3 to 25 carbon atoms (such as 2-1,3-diethylimidazoyl, 2-1,3-dimethylimidazoyl, 2-1-methylbenzoimidazoyl, 2-1,3,4-triethylimidazoyl, 2-1,3-diethylbenzoimidazoyl, 2-1,3,5-trimethylbenzoimidazoyl, 2-6-chloro-1,13-dimethylbenzoimidazoyl, 2-5,6-dichloro-1,3-diethylbenzoimidazoyl, and 2-1,3-disulfopropyl-5-cyano-6-chlorobenzoimidazoyl), an indolenine nucleus having from 10 to 30 carbon atoms (such as 3,3-dimethylindolenine), a quinoline nucleus having from 9 to carbon atoms (such as 2-1-methylquinolyl, 2-1-methylquinolyl, 2-1-ethyl-6-chloroquinolyl, 2-1,3-diethylquinolyl, 2-1-methyl-6-methylthioquinolyl, 2-1-sulfopropylquinolyl, 4-1-methylquinolyl, 4-1-sulfoethylquinolyl, 4-1-methyl-7-chloroquinolyl, 4-1,8-diethylquinolyl, 4-1-methyl-6-methylthioquinolyl, and 4-1-sulfopropylquinolyl), a selenazole nucleus having from 3 to 25 carbon atoms (such as 2-3-methylbenzoselenazolyl), and a pyridine nucleus having from 5 to 25 carbon atoms (such as 2-pyridyl). In addition, there are enumerated a thiazoline nucleus, an oxazoline nucleus, a selenazoline nucleus, a tellurazoline nucleus, a tellurazole nucleus, a benzotellurazole nucleus, an imidazoline nucleus, an imidazo[4,5-quinoxaline] nucleus, an oxadiazole nucleus, a thiadiazole nucleus, a tetrazole nucleus, and pyrimidine nucleus.
These nuclei may have a substituent. As the substituent, those enumerated above for W are enumerated. Preferred examples of the substituent include an alkyl group (such as methyl, ethyl, and propyl), a halogen atom (such as chlorine, bromine, iodine, and fluorine), a nitro group, an alkoxy group (such as methoxy and ethoxy), an aryl group (such as phenyl) a heterocyclic group (such as 2-pyridyl, 3-pyridyl, 1-pyrrolyl, and 2-thienyl), an aryloxy group (such as phenoxy), an acylamino group (such as acetylamino and benzoylamino), a carbamoyl group (such as N,N-dimethylcarbamoyl), a sulfo group, a sulfonamide group (such as methanesulfonamide), a sulfamoyl group (such as N-methylsulfamoyl), a hydroxyl group, a carboxy group, an alkylthio group (such as methylthio), and a cyano group.
Among them, are more preferable an oxazole nucleus, an imidazole nucleus, and a thiazole nucleus. These heterocyclic rings may further be fused. Examples of the ring to be fused include a benzene ring, a benzofuran ring, a pyridine ring, a pyrrole ring, an indole ring, and a thiophene ring.
Za4, Za5 and Za6 each represents an atomic group forming an acid nucleus, which is defined according to James, ed., The Theory of the Photographic Process, 4th Edition, Macmillan, 1977, page 198. Specific examples include nuclei such as 2-pyrazolon-5-one, pyrazolidine-3,5-dione, imidazolin-5-one, hydantoin, 2- or 4-thiohydantoin, 2-iminooxazolidin-4-one, 2-oxazolin-5-one, 2-thioxazoline-2,4-dione, isorhodanine, rhodanine, indane-1,3-dione, thiophen-3-one, thiophen-3-one-1,1-dioxide, indolin-2-one, indolin-3-one, 2-oxoindazolium, 5,7-dioxo-6,7-dihydrothiazolo[3,2-a]-pyrimidine, 3,4-dihydroisoquinolin-4-one, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, courmarin-2,4-dione, indazolin-2-one, pyrido-[1,2-a]pyrimidine-1,3-dione, pyrazolo[1,5-b]quinazolone, and pyrazolopyridone.
Among them are preferable hydantoin, rhodanine, barbituric acid, and 2-oxazolin-5-one. Za4 is preferably barbituric acid.
As specific examples of the cyanine chromophore, merocyanine chromophore and oxonol chromophore, are enumerate those described in F. M. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John Wiley and Sons, Yew York, London (1964).
As the formulae of the cyanine dyes and merocyanine dyes, are enumerated the formulae (XI), and (XII) given at pages 21 to 22 of U.S. Pat. No. 5,340,694 (however, the number of each of n12 and n15 is not limited, but is an integer of 0 or more (preferably an integer of from 0 to 4)).
Dye2 represents a xanthene dye. The xanthene dye is preferably represented by the formula (2).
In the formula, X3 represents an oxygen atom or a sulfur atom, and preferably an oxygen atom.
R11 represents any one of xe2x80x94OM, xe2x80x94SM, and xe2x80x94NR2OR21; R12 represents any one of xe2x95x90O, xe2x95x90S, and xe2x95x90+NR22R23; M represents a proton or a cation (preferred examples are the same as in the cation for CI as described later); and R20 to R23 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group (preferred examples are the same as in R3 to R5), and preferably a hydrogen atom, an alkyl group, or an aryl group.
R20 and R21, or R22 and R23 may be linked to each other to form a ring. Preferred examples of the ring to be formed include a piperidine ring, a pyrrolidine ring, a morpholine ring, and a piperazine ring.
Preferably, R20 and R22 each represents an alkyl group or an aryl group, more preferably an alkyl group, and most preferably an ethyl group.
Preferably, R21 and R23 each represents a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or an ethyl group.
Preferably, R11 represents xe2x80x94OM or xe2x80x94NR2OR21, and R12 represents xe2x95x90O or xe2x95x90+NR22R23. It is preferred that when R1 represents xe2x80x94OM, R12 represents xe2x95x90O and that when R1, represents xe2x80x94NR2OR21, R12 represents xe2x95x90+NR22R23.
R13 to R19 each independently represents a hydrogen atom or a substituent. As the substituent, any of those enumerated above for W may be used. Preferred examples include an alkyl group having from 1 to 20 carbon atoms (preferred examples are the same as in R3 to R5), an aryl group having from 6 to 20 carbon atoms (such as phenyl and 2-naphthyl), a heterocyclic group having from 0 to 20 carbon atoms (such as 2-pyridyl, 3-pyridyl, 1-pyrrolyl, and 2-thienyl), a halogen atom (such as chlorine, bromine, iodine, and fluorine), an alkoxy group having from 1 to 20 carbon atoms (such as methoxy and ethoxy), an aryloxy group having from 6 to 20 carbon atoms (such as phenoxy, 1-naphthoxy, and 2-naphthoxy), an alkylthio group having from 1 to 20 carbon atoms (such as methylthio), an amino group having from 0 to 20 carbon atoms (such as an amino group, an N-ethylamino group, an N,N-diethylamino group, and an anilino group), an acylamino group having from 1 to 20 carbon atoms (such as acetylamino and benzoylamino), a carbamoyl group having from 1 to 20 carbon atoms (such as N,N-dimethylcarbamoyl), an alkoxycarbonyl group having from 2 to 20 carbon atoms (such as ethoxycarbonyl), a sulfonamide group having from 0 to 20 carbon atoms (such as methanesulfonamide), a sulfamoyl group having from 0 to 20 carbon atoms (such as N-methylsulfamoyl), a nitro group, a sulfo group, a hydroxyl group, a carboxyl group, and a cyano group.
Preferably, R14, R15, R17, and R18 each represents a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group, a sulfo group, a hydroxyl group, or a cyano group, and more preferably a hydrogen atom, an alkyl group, a halogen atom, or a sulfo group.
Preferably, R16 and R19 each represents a hydrogen atom.
R13 preferably represents an unsubstituted or substituted aryl group, more preferably a phenyl group substituted with any one of a carboxyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfo group, a halogen atom, an amino group, a hydroxyl group, an alkyl group, and an alkoxy group, and most preferably a phenyl group substituted with at least one of a carboxyl group, an alkoxycarbonyl group, and a carbamoyl group.
In R11, to R19, the adjacent substituents may be linked to each other to form a ring. Preferred examples of the ring to be formed include a benzene ring, a naphthalene ring, a cyclohexane ring, a cyclopentane ring, a pyridine ring, a pyrazine ring, a piperidine ring, a pyrrolidine ring, an oxazole ring, a thiazole ring, an imidazole ring, and a dioxane ring.
When R11, represents xe2x80x94OM, and R12 represents xe2x95x90O, it is more preferable that all of R14, R15, R17, and R18 represent a halogen atom.
When R11 represents xe2x80x94NR2OR21, and R12 represents xe2x95x90+NR22R23, it is more preferable that R14, R15, R17, and R18 each independently represents a hydrogen atom or an alkyl group.
More preferably, the compound represented by the formula (1) according to the invention is represented by the formula (3).
In the formula, X3 and R11 to R19 are synonymous with those in (2) as above, and G1, G2, A1, and t1 are synonymous with those in (11) as above.
X1 and X2 each independently represents xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NR6xe2x80x94, or xe2x80x94CR7R8xe2x80x94; and R6 to R8 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic ring (preferred examples are the same as in R3 to R5). R6 preferably represents a hydrogen atom, an alkyl group, or a sulfoalkyl group, and more preferably an alkyl group or a sulfoalkyl group. Preferably, R7 and R8 each represents an alkyl group.
Preferably, X1 and X2 each represents xe2x80x94Oxe2x80x94 or xe2x80x94Sxe2x80x94, and more preferably xe2x80x94Oxe2x80x94.
R1 and R2 each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heterocyclic ring (preferred examples are the same as in R3 to R5), and preferably a hydrogen atom, an alkyl group, or an acid-substituted alkyl group (examples of the acid group include a carboxy group, a sulfo group, a phosphato group, a sulfonamide group, a sulfamoyl group, and an acylsulfonamide group). As the acid-substituted alkyl group is preferable a sulfoalkyl group.
More preferably, R1 and R2 each represents an alkyl group or a sulfoalkyl group.
M1 to M3 each independently represents a methine group (preferred examples are the same as in Ma1 to Ma14), and preferably an unsubstituted, ethyl group-substituted or methyl group-substituted methine group.
n1 represents an integer of from 0 to 3, preferably an integer of from 0 to 2, and more preferably 0 or 1. When n1 is 2 or more, M1s"" and M2s"" may be respectively the same or different.
When n1 is 0, it is preferred that both of X1 and X2 represent xe2x80x94Sxe2x80x94. When n1 is 1, preferably, both of X1 and X2 represent xe2x80x94Oxe2x80x94, or either one of X1 or X2 represents xe2x80x94Oxe2x80x94, and the other represents xe2x80x94Sxe2x80x94, and more preferably, both of X1 and X2 represent xe2x80x94Oxe2x80x94.
V1 and V2 each represents a substituent, and any of those enumerated above for W may be used any of those enumerated above for W may be used. Preferred examples of the substituent include an alkyl group having from 1 to 20 carbon atoms (preferred examples are the same as in R3 to R5), an aryl group having from 6 to 20 carbon atoms (such as phenyl and 2-naphthyl), a heterocyclic group having from 0 to 20 carbon atoms (such as 2-pyridyl, 3-pyridyl, 1-pyrrolyl, and 2-thienyl), a halogen atom (such as chlorine, bromine, iodine, and fluorine), an alkoxy group having from 1 to 20 carbon atoms (such as methoxy and ethoxy), an aryloxy group having from 6 to 20 carbon atoms (such as phenoxy, 1-naphthoxy, and 2-naphthoxy), an alkylthio group having from 1 to 20 carbon atoms (such as methylthio), an acylamino group having from 1 to 20 carbon atoms (such as acetylamino and benzoylamino), a carbamoyl group having from 1 to 20 carbon atoms (such as N,N-dimethylcarbamoyl), a sulfonamide group having from 0 to 20 carbon atoms (such as methanesulfonamide), a sulfamoyl group having from 0 to 20 carbon atoms (such as N-methylsulfamoyl), a nitro group, a sulfo group, a hydroxyl group, a carboxyl group, and a cyano group. Preferably, V1 and V2 each represents an alkyl group, a halogen atom (particularly chlorine and bromine), an aryl group, an acylamino group, a carbamoyl group, or an alkoxy group. A preferred substitution position is the 5- or 6-position.
n2 and n3 each represents an integer of from 0 to 4, and preferably an integer of from 0 to 2. When each of n2 and n3 is 2 or more, V1s"" and V2s"" may be respectively the same or different, or may be respectively taken together to form a ring. Preferred examples of the ring to be formed include a benzene ring, a pyridine ring, a benzofuran ring, a thiophene ring, a pyrrole ring, and an indole ring, with a benzene ring being more preferred.
CI represents an ion for neutralizing a charge. Whether a certain compound is a cation or an anion, or it has a net ionic charge, relies on its substituent. A typical cation is an ammonium ion or an alkali metal ion, whereas an anion may be any of an inorganic ion and an organic ion.
Examples of the cation include a sodium ion, a potassium ion, a triethylammonium ion, a diethyl (isopropyl) ammonium ion, a pyridinium ion, and a 1-ethylpyridinium ion; and examples of the anion include a halogen anion (such as a chlorine ion, a bromine ion, a fluorine ion, and an iodine ion), a substituted arylsulfonic acid ion (such as p-toluenesulfonic acid ion), an alkyl sulfate ion (such as a methyl sulfate ion), a sulfuric acid ion, a perchloric acid ion, a tetrafluoroboric acid ion, and an acetic acid ion. y represents the number necessary for neutralizing the charge.
G1 is linked to Dye1 at R1 or V1, and G2 is linked to Dye2 at any one of R11 to R19. Here, groups, in which one hydrogen atom has been eliminated from the terminal of each of G1, G2, R1, V1, and R11, to R19, are linked to each other. However, this does not always mean that the compound be produced by such a synthesis method.
Preferred examples of V1 to be linked to G1 include a carboxy group, an alkoxy group, an acylamino group, a carbamoyl group, a sulfonamide group, a sulfamoyl group, a hydroxyl group, and an alkylthio group, with an acylamio group and a carbamoyl group being more preferred. Preferably, G1 is linked to R1.
Preferably, G2 is linked to R13. At this time, R13 preferably represents a phenyl group substituted with a carboxyl group or a carbamoyl group. It is preferred that R13 is linked to G2 via this carboxyl group or carbamoyl group.
In the compound represented by the formula (1) or (3) according to the invention, preferred examples of Dye1 will be given below, but it should not be construed that the invention is limited thereto. Incidentally, the structural formula of each of the compounds of the invention as described below is merely one limiting structure of resonance structures which the compound of the invention can take, and the compound may take other structure which it can take by resonance.
In the compound represented by the formula (1) or (2) according to the invention, preferred examples of the xanthene dye, Dye2 will be given below, but it should not be construed that the invention is limited thereto.
In the compound represented by the formula (1) or (3) according to the invention, preferred examples of the linking group, -L1xe2x80x94 will be given below, but it should not be construed that the invention is limited thereto.
Examples of the linking group, -L1- (the left side means Dye1):
Specific examples of the compound represented by the formula (1) or (3) according to the invention will be given below, but it should not be construed that the invention is limited thereto.
Examples of the compound, Dye1-L-Dye2 according to the invention:
For example, the compound of the invention can be synthesized according to the methods described in F. M. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John Wiley and Sons, Yew York, London (1964); D. M. Sturmer, Heterocyclic Compounds-Special Topics in Heterocyclic Chemistry, Chapter 18, Section 14, pages 482 to 515, John Wiley and Sons, Yew York, London (1977); and European Patent No. 87700A1.
In the compound represented by the formula (1) or (3), an adsorptivity to silver halide grains is in the relationship of Dye1 greater than Dye2. Incidentally, the adsorptivity to silver halide grains can be determined by using the respective model compound.
When Dye2 of the compound represented by the formula (1) or (3) is light excited, it is preferred that Dye2 can cause electron tansfer or energy transfer to Dye1.
Further, it is preferred that in silver halide photographic emulsions and silver halide photographic materials, the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1, and Dye2 not adsorbed on the silver halide grains causes electron transfer or energy transfer to Dye1 upon light excitation.
Moreover, it is preferred that in silver halide photographic emulsions and silver halide photographic materials, the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1 to form J association.
In addition, it is preferred that in silver halide photographic emulsions, when the compound represented by the formula (1) or (3) is adsorbed on the silver halide grains by Dye1, Dye2 keeps a monomer state in an adsorbing spectral manner.
Next, the silver halide photographic material of the invention will be described below in detail.
The compound of the invention is used mainly as a sensitizing dye in silver halide emulsions and silver halide photographic materials.
The compound of the invention can be used singly or in admixture of two or more thereof, or can be used in combination with other sensitizing dye for the silver halide emulsion or silver halide photographic material. Preferred examples of the dye to be used include cyanine dyes, merocyanine dyes, rhodacyanine dyes, trinuclear merocyanine dyes, tetranuclear merocyanine dyes, allopolar dyes, hemicyanine dyes, and styryly dyes. Among them are more preferable cyanine dues, merocyanine dyes, and rhodacyanine dyes, with cyanine dyes being most preferred. The details of these dyes are described in, for example, F. M. Harmer, Heterocyclic Compounds-Cyanine Dyes and Related Compounds, John Wiley and Sons, Yew York, London (1964); D. M. Sturmer, Heterocyclic Compounds-Special Topics in Heterocyclic Chemistry, Chapter 18, Section 14, pages 482 to 515, John Wiley and Sons, Yew York, London (1977); and Rodd""s Chemistry of Carbon Compounds, 2nd. Ed., Vol. IV, Part B (1977), Chapter 15, pages 369 to 422, Elsevier Science Publishing Company Inc., New York.
As the preferred dye are enumerated sensitizing dyes represented by the formulae and enumerated as specific examples at pages 32 to 44 of U.S. Pat. No. 5,994,051 and at pages 30 to 39 pages of U.S. Pat. No. 5,747,236.
Further, as the formulae of preferred cyanine dyes, merocyanine dyes and rhodacyanine dyes, are enumerated the formulae (XI), (XII) and (XIII) given in columns 21 to 22 of U.S. Pat. No. 5,340,694 (however, the number of each of n12, n15, n17 and n18 is not limited, but is an integer of 0 or more (preferably 4 or less)).
These sensitizing dyes may be used singly or in admixture of two or more thereof. A combination of the sensitizing dyes is often employed especially for the purpose of super-sensitization. Representative examples are described in U.S. Pat. Nos. 2,688,545, 2,977,229, 3,397,060, 3,522,052, 3,527,641, 3,617,293, 3,628,964, 3,666,480, 3,672,898, 3,679,428, 3,003,377, 3,769,301, 3,814,609, 3,837,862 and 4,026,707, British Patent Nos. 1,344,281 and 1,507,803, JP-B-43-49336, JP-B-53-12375, JP-A-52-110618, and JP-A-52-109925.
The emulsion may contain a dye that does not have a spectral sensitizing action itself, or a substance that does not substantially absorb a visible light but exhibits supersensitization, together with the sensitizing dye.
A supersensitizer useful for the spectral sensitization in the invention (such as pyrimidylamino compounds, triazinylamino compounds, azolium compounds, aminostyryl compounds, aromatic organic acid-formaldehyde condensates, azaindene compounds, and cadmium compounds) and a combination of the supersensitizer with the sensitizing dye are described in, for example, U.S. Pat. Nos. 3,511,646, 3,615,613, 3,615,632, 3,615,641, 4,596,767, 4,945,038, 4,965,182, 4,965,182, 2,933,390, 3,635,721, 3,743,510, 3,617,295, and 3,635,721. With respect to the method of use thereof, the methods as described in these patents are preferred.
The timing of adding the sensitizing dye of the invention (similarly other sensitizing dye and supersensitizer) to the silver halide emulsion of the invention may be any stages of the preparation of the emulsion, which have been admitted to be useful up to date. For example, the sensitizing dye may be added at any timing or during any step before application of the emulsion, such as during the step of formation of silver halide grains or/and at the timing before desalting, or during the step of desalting and/or at the timing after desalting but before the start of chemical ripening, as disclosed in U.S. Pat. Nos. 2,735,766, 3,628,960, 4,183,756 and 4,225,666, JP-A-58-184142, and JP-A-60-196949; and at the timing just before chemical ripening or during chemical ripening, or at the timing after chemical ripening until the application, as disclosed in JP-A-58-113920. Further, as disclosed in U.S. Pat. No. 4,225,666 and JP-A-58-7629, the same compound may be added singly or in combination of a compound of a different kind of structure, for example, dividedly during the step of grain formation and during the step of chemical ripening or after completion of chemical ripening, or before or during the step of chemical ripening and after completion of chemical ripening. Moreover, the sensitizing dye may be added by changing the kind of the compound or combination of the compounds to be dividedly added.
The addition amount of the sensitizing dye of the invention (similarly other sensitizing dye and supersensitizer) varies depending on the shape and size of the silver halide grains, and any addition amount may be employed. Preferably, the sensitizing dye can be added in an amount of from 1xc3x9710xe2x88x928 to 8xc3x9710xe2x88x921 moles per mole of the silver halide. For example, in the case where the grain size of the silver halide is from 0.2 to 1.3 xcexcm, the addition amount of the sensitizing dye is preferably from 2xc3x9710xe2x88x926 to 3.5xc3x9710xe2x88x923 moles, and more preferably from 7.5xc3x9710xe2x88x926 to 1.5xc3x9710xe2x88x923 moles per mole of the silver halide.
The sensitizing dye of the invention (similarly other sensitizing dye and supersensitizer) can be dispersed directly in the emulsion. Also, the sensitizing dye can be first dissolved in a proper solvent (such as methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine, and mixed solvents thereof) and then added in a state of solution to the emulsion. At this time, additives such as bases, acids, and surfactants can be made present jointly. For the dissolution, ultrasonic waves may be employed. As the method of adding this compound, there are employed a method in which the compound is dissolved in a volatile organic solvent, the solution is dispersed in a hydrophilic colloid, and the dispersion is added to the emulsion, as disclosed in U.S. Pat. No. 3,469,987; a method in which the compound is dispersed in a water-soluble solvent, and the dispersion is added to the emulsion, as disclosed in JP-B-46-24185; a method in which the compound is dissolved in a surfactant, and the solution is added to the emulsion, as disclosed in U.S. Pat. No. 3,822,135; a method in which the compound is dissolved using a compound to cause red shifting, and the solution is added to the emulsion, as disclosed in JP-A-51-74624; and a method in which the compound is dissolved in an acid not substantially containing water, and the solution is added to the emulsion, as disclosed in JP-A-50-80826. Besides, for the addition to the emulsion, methods as disclosed in U.S. Pat. Nos. 2,912,343, 3,342,605, 2,996,287 and 3,429,835 are employable.
In the invention, for the photographic emulsion that is in charge of the sensitization mechanism, any of silver bromide, silver iodobromide, silver chlorobromide, silver iodide, silver iodochloride, silver iodobromochloride, and silver chloride can be used as the silver halide. When the halogen composition of the outermost surface layer of the emulsion has an iodine content of preferably 0.1 mole % or more, more preferably 1 mole % or more, and most preferably 5 mole % or more, it is possible to construct a stronger multilayered adsorption structure.
The grain size distribution may be broad or narrow, but preferably narrow.
The silver halide grains of the photographic emulsion may be any of grains having a regular crystal form (such as cube, octahedron, tetradecahedron, and rhombic dodecahedron), grains having an irregular crystal form (such as sphere and table), grains having a higher-order plane ((hk1) plane), and mixtures of these grains. Preferably, the silver halide grains are tabular grains, and the details of the tabular grains will be described below. With respect to the grains having a higher-order plane, the description of Journal of Imaging Science, Vol. 30 (1986), pages 247 to 254 can be referred to.
Further, the silver halide photographic emulsion to be used in the invention may contain the foregoing silver halide grains singly or in admixture. The silver halide grains may have a structure in which the interior and the surface layer are made of a different phase; may have a multi-phase structure of a junction structure; may have a localized phase on the grain surface; may be made of a uniform phase over the whole of grain; or may be a mixture thereof.
These various emulsions may be of a surface latent image type in which a latent image is chiefly formed on the surface or of an internal latent image type in which the latent image is formed inside the grain.
In the invention, tabular silver halide grains whose halogen composition is silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide, or silver iodochloride are preferably used. As the tabular grains are preferable ones having a (100) or (111) main surface. A tabular grain having a (111) main surface (hereinafter referred to as xe2x80x9c(111) tabular grainxe2x80x9d) generally has a triangle or hexagonal plane. In general, the more uniform the distribution, the higher the ratio of the tabular grains is. The hexagonal monodispersed tabular grain is described in JP-B-5-61205.
A tabular grain having a (100) plane as the main surface (hereinafter referred to as xe2x80x9c(100) tabular grainxe2x80x9d) has a rectangular or square form. In this emulsion, grains having an adjacent edge ratio less than 5:1 as compared with needle grains are called a tabular grain. In tabular grains of silver chloride or those containing a large quantity of silver chloride, the (100) tabular grain is originally higher in stability of the main surface than the (111) tabular grain. In the case of the (111) tabular grain, it is necessary to stabilize the (111) main surface. Such is described in JP-A-9-80660, JP-A-9-80656, and U.S. Pat. No. 5,298,388.
The (111) tabular grain of silver chloride or containing a high content of silver chloride is disclosed in U.S. Pat. Nos. 4,414,306, 4,400,463, 4,713,323, 4,783,398, 4,962,491, 4,983,508, 4,804,621, 5,389,509, 5,217,858 and 5,460,934.
The (111) tabular grain having a high content of silver bromide is disclosed in U.S. Pat. Nos. 4,425,425, 4,425,426, 443,426, 4,439,520, 4,414,310, 4,430,048, 4,647,528, 4,665,012, 4,672,027, 4,678,745, 4,684,607, 4,593,964, 4,722,886, 4,722,886, 4,755,617, 4,755,456, 4,806,461, 4,801,522, 4,835,322, 4,839,268, 4,914,014, 4,962,015, 4,977,074, 4,985,350, 5,061,609, 5,061,616, 5,068,173, 5,132,203, 5,272,048, 5,334,469, 5,334,495, 5,358,840, and 5,372,927.
The (100) tabular grain to be used in the invention is disclosed in U.S. Pat. Nos. 4,386,156, 5,275,930, 5,292,632, 5,314,798, 5,320,938, 5,319,635 and 5,356,764, European Patent Nos. 569,971 and 737,887, JP-A-6-308648, and JP-A-9-5911.
As the silver halide emulsion to be used in the invention, are preferable tabular silver halide grains having a higher surface area/volume ratio, on which the sensitizing dye of the invention has been adsorbed. The tabular silver halide grain preferably has an aspect ratio of 2 or more, more preferably 5 or more, and most preferably 8 or more. Though the upper limit of the aspect ratio of the tabular silver halide grain is not particularly limited, it is preferably 1,000 or less, and more preferably 500 or less. The thickness of the tabular grain is preferably less than 0.2 xcexcm, more preferably less than 0.1 xcexcm, and most preferably less than 0.07 xcexcm.
Here, what the aspect ratio of 2 or more means that silver halide grains having an aspect ratio (circle-corresponding diameter/grain thickness) of 2 or more account for 50% or more, preferably 70% or more, and most preferably 85% or more of the projected area of the whole of silver halide grains in the emulsion.
In order to prepare such thin tabular grains having a high aspect ratio, the following technologies are applicable.
In the tabular grains of the invention, it is desired that the dislocation line amount distribution between the grains is uniform. In the emulsion of the invention, the silver halide grains containing 10 or more dislocation lines per grain preferably account for from 100 to 50% (the number), more preferably from 100 to 70%, and most preferably from 100 to 90% of the whole of grains. A proportion of less than 50% is not desired from the viewpoint of uniformity between the grains.
In the invention, in the case of the proportion of the dislocation line-containing grains and the number of dislocation lines are determined, they are determined by directly observing the dislocation lines preferably with respect to at least 100 grains, more preferably with respect to 200 or more grains, and most preferably with respect to 300 or more grains.
As a protective colloid that is used during the preparation of the emulsion of the invention and a binder of other hydrophilic colloid layer, it is advantageous to use gelatin, but other hydrophilic colloids can be used.
Examples of the hydrophilic colloid that can be used include proteins such as gelatin derivatives, graft polymers of gelatin and other polymer, albumin, and casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfates; sugar derivatives such as sodium alginate and starch derivatives; and various synthetic hydrophilic polymer substances such as homopolymers and copolymers (e.g., polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole).
As the gelatin, are employable lime-processed gelatin, acid-processed gelatin, and enzyme-processed gelatin as described in Bull. Soc. Sci. Photo., Japan, No. 16, page 30 (1966). Also, hydrolyzates and enzymatic decomposition products of gelatin can be used.
In order to perform desalting, it is preferred that the emulsion of the invention is rinsed with water and dispersed in a newly prepared protective colloid. The temperature for water rinsing may be chosen depending on the purpose, but is preferably selected from the range of from 5xc2x0 C. to 50xc2x0 C. The pH during the water rinsing may be chosen depending on the purpose, but is preferably selected from the range of from 2 to 10, and more preferably from 3 to 8. The pAg during the water rinsing may be chosen depending on the purpose, but is preferably selected from the range of from 5 to 10. The water rinsing can be selected from a noodle washing method, a dialysis method using a semi-permeable membrane, a centrifugal method, a coagulation sedimentation method, and an ion exchange method. In the case of the coagulation sedimentation method, it can be selected from a method of using a sulfate, a method of using an organic solvent, a method using a water-soluble polymer, and a method of using a gelatin derivative.
During the preparation of the emulsion of the invention, it is preferred depending on the purpose to make a metal ion salt present during the grain formation, desalting step or chemical sensitization, or before the application. In the case of doping the grains, it is preferred to add the metal ion salt during the grain formation. During modification of the grain surface or use as a chemical sensitizer, the metal ion salt is preferably added after the grain formation but before completion of the chemical sensitization. Also, a method of doping the whole of grains or a method of doping only the core section of grain or only the shell section of grain may be selected. Examples of the metal that can be used include Mg, Ca, Sr, Ba, Al, Sc, Y, La, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ru, Rh, Pd, Re, Os, Ir, Pt, Au, Cd, Hg, Tl, In, Sn, Pb, and Bi. These metals can be added in a state of salt that can be dissolved during the grain formation, such as ammonium salts, acetates, nitrates, sulfates, phosphates, hydrides, hexa-coordinated complex salts, and tetra-coordinated complex salts. Examples of metal salt include CdBr2, CdCl2, Cd(NO3)2, Pb(NO3)2, Pb(CH3COO)2, K3[Fe(CN)6], (NH4)4[Fe(CN)6], K3IrCl6, (NH4)3RhCl6, and K4Ru(CN)6. A ligand of the coordinated compound can be selected from halo, aquo, cyano, cyanate, thiocyanate, nitrosyl, thionitrosyl, oxo, and carbonyl. These metal compounds can be used singly or in admixture of two or more thereof.
Preferably, the metal compound is dissolved in a proper organic solvent such as methanol and acetone and then added. In order to stabilize the solution, there can be employed a method in which a hydrogen halide aqueous solution (such as HCl and HBr) or a halogenated alkali (such as KCl, NaCl, Kbr, and NaBr) is added. If desired, an acid or an alkali may be added. The metal compound may be added to a reaction vessel before the grain formation or on the way of the grain formation. Further, the metal compound can be added to a water-soluble silver salt (such as AgNO3) or a halogenated alkali aqueous solution (such as NaCl, KBr, and KI) and continuously added during the formation of silver halide grains. Moreover, the water-soluble silver salt and the halogenated alkali may be prepared as independent solutions and then continuously added at a proper timing during the grain formation. In addition, it is also preferred to combine various addition methods.
There may be the case where a method of adding a chalcogen compound during the preparation of emulsion as disclosed in U.S. Pat. No. 3,772,031 is useful. In addition to S, Se and Te, cyan salts, thiocyan salts, selenocyan salts, carbonates, phosphates, or acetates may be contained.
The silver halide grains of the invention can be subjected to at least one of sulfur sensitization, selenium sensitization, gold sensitization, palladium sensitization, noble metal sensitization, and reduction sensitization at an arbitrary stage of the production process of silver halide emulsion. It is preferred to combine two or more sensitization methods. It is possible to prepare various types of emulsions by regulating the timing of the chemical sensitization. There are a type in which a chemical sensitization nucleus is embedded in the grain, a type in which a chemical sensitization nucleus is embedded in a position shallow from the grain surface, and a type in which a chemical sensitization nucleus is prepared on the grain surface. In the emulsion of the invention, if desired, the place of the chemical sensitization nucleus can be chosen, but it is preferred to prepare at least one chemical sensitization nucleus in the vicinity of the grain surface.
As one of examples of the chemical sensitization that can be preferably carried out in the invention, chalcogen sensitization and noble metal sensitization can be employed singly or in combination. For example, the chemical sensitization can be carried out by using active gelatin, as described in T. H. James, The Theory of the Photographic Process, 4th ed., Macmillan (1977), pages 67 to 76; and it can be carried out by using sulfur, selenium, tellurium, gold, platinum, palladium, or iridium, or a combination of a plurality of these chemical sensitizers at a pAg of from 5 to 10 and at a pH of from 5 to 8 at a temperature of from 30 to 80xc2x0 C., as described in Research Disclosure, Vol. 120, April 1974, 12008, Research Disclosure, Vol. 34, June 1975, 13452, U.S. Pat. Nos. 2,642,361, 3,297,446, 3,772,031, 3,857,711, 3,901,714, 4,266,018 and 3,904,415, and British Patent No. 1,315,755. In the noble metal sensitization, salts of noble metals such as gold, platinum, palladium, and iridium can be used. Especially, gold sensitization and palladium sensitization as well as a combination of the both are preferred. In the case of the gold sensitization, known compounds such as auric chloride, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, and gold selenide can be used. The palladium compound means a divalent or tetravalent palladium salt. The preferred palladium compound is represented by R2PdX6 or R2PdX4, wherein R represents a hydrogen atom, an alkali metal atom, or an ammonium group; and X represents a halogen atom such as a chlorine atom, a bromine atom, and an iodine atom.
Specifically, are preferable K2PdCl4, (NH4)2PdCl6, Na2PdCl4, (NH4)2PdCl4, Li2PdCl4, Na2PdCl6, and K2PdBr4. The gold compound and the palladium compound are preferably used in combination with a thiocyanate or a selenocyanate.
Examples of the sulfur sensitizer include hypo, thiourea-based compounds, rhodanine-based compounds, and sulfur-containing compounds as described in U.S. Pat. Nos. 3,857,711, 4,266,018 and 4,054,457. As a useful chemical sensitization assistant, are employable compounds that are known to retard fogging during the chemical sensitization and increase the sensitivity, such as azaindenes, azapyridazines, and azapyrimidines. Examples of chemical sensitization assistant modifiers are described in U.S. Pat. Nos. 2,131,038, 3,411,914 and 3,554,757, JP-A-58-126526, and Duffin, Photographic Emulsion Chemistry, pages 138 to 143.
Preferably, the emulsion of the invention is used in combination of the gold sensitization. A preferred amount of the gold sensitizer is from 1xc3x9710xe2x88x924 to 1xc3x9710xe2x88x927 moles, and more preferably from 1xc3x9710xe2x88x925 to 5xc3x9710xe2x88x927 moles. A preferred amount of the palladium compound is in the range of from 1xc3x9710xe2x88x923 to 5xc3x9710xe2x88x927 moles. A preferred amount of the thiocyan compound or selenocyan compound is in the range of from 5xc3x9710xe2x88x922 to 1xc3x9710xe2x88x926 moles.
A preferred amount of the sulfur sensitizer that is used for the silver halide grains of the invention is from 1xc3x9710xe2x88x924 to 1xc3x9710xe2x88x927 moles, and more preferably from 1xc3x9710xe2x88x925 to 5xc3x9710xe2x88x927 moles per mole of the silver halide.
As the sensitization for the emulsion of the invention, selenium sensitization is preferable. In the selenium sensitization, known instable selenium compounds can be used. Specific examples of the selenium compound include colloidal metallic selenium, selenoureas (such as N,N-dimethylselenourea and N,N-diethylselenourea), selenoketones, and selenoamides. There may be the case where it is preferred to combine the selenium sensitization with sulfur sensitization or noble metal sensitization or a combination of the both.
Preferably, the silver halogen emulsion of the invention is subjected to reduction sensitization during the grain formation, after the grain formation and before or during the chemical sensitization, or after the chemical sensitization.
Here, as the reduction sensitization, any of a method in which a reduction sensitizer is added to the silver halide emulsion, a method called silver ripening, in which the silver halide emulsion is grown or ripened in a low-pAg atmosphere at a pAg of from 1 to 7, and a method called high-pH ripening, in which the silver halide emulsion is grown or ripened in a high-pH atmosphere at a pH of from 8 to 11 can be used. A combination of two or more of these methods can also be employed.
The method of adding the reduction sensitization is preferred from the standpoint that the level of the reduction sensitization can be delicately regulated.
As the reduction sensitizer, for example, stannous salts, ascorbic acid and derivatives thereof, amines and polyamines, hydrazine derivatives, formamidinesulfinic acid, silane compounds, and borane compounds. These compounds may be used in admixture of two or more thereof. Preferred examples of the reduction sensitizer include stannous chloride, thiourea dioxide, dimethylamineborane, and ascorbic acid and derivatives thereof. The addition amount of the reduction sensitizer relies upon the production conditions of emulsion. Accordingly, it is required to select the addition amount of the reduction sensitizer, but it is suitably in the range of from 10xe2x88x927 to 10xe2x88x923 moles per mole of the silver halide.
For example, the reduction sensitizer is dissolved in water or an organic solvent (such as alcohols, glycols, ketones, esters, and amides) and added during the grain growth. Though the reduction sensitizer may be added in advance to a reaction vessel, a method of adding it at a proper timing during the grain growth. Further, there may be employed a method in which the reduction sensitizer is added in advance in an aqueous solution of a water-soluble silver salt or water-soluble alkali halide, and the silver halide grains are precipitated using the resulting aqueous solution. Moreover, a method in which a solution of the reduction sensitizer is dividedly added with the growth of grains or continuously added over a long period of time is also preferred.
Preferably, an oxidizing agent to silver is added in the production step of the emulsion of the invention. The oxidizing agent to silver as referred to herein means a compound having an action such that it acts to metallic silver and converts it into a silver ion. Especially, compounds capable of converting extremely fine silver grains formed as a by-product during the formation step of the silver halide grains and the chemical sensitization step into a silver ion are effective. The silver ion as formed may form sparingly water-soluble silver salts such as silver halides, silver sulfide, and silver selenide, or may form water-soluble silver salts such as silver nitrate. The oxidizing agent to silver may be any of an inorganic material and an organic material. Examples of the inorganic oxidizing agent include ozone; hydrogen peroxide and adducts thereof (such as NaBO2.H2O2.3H2O, 2NaCO3.3H2O2, Na4P2O7.2H2O2, and 2Na2SO4.H2O2.2H2O); oxyacid salts such as peroxy acid salts (such as K2S2O8, K2C2O6, and K2P2O8), peroxy complex compounds (such as K2[Ti (O2) C2O4].3H2O, 4K2SO4.Ti(O2)OH.SO4.2H2O, and Na3[VO(O2) (C2H4)2].6H2O), permanganates (such as KMnO4), chromates (such as K2Cr2O7) halogen elements such as iodine and bromine; perhalic acid salts (such as potassium periodate), salts of high-valence metals (such as hexacyanoferric acid potassium), and thiosulfonic acid salts.
Examples of the organic oxidizing agent include quinones such as p-quinone; organic peroxides such as peracetic acid and perbenzoic acid; and compounds capable of releasing an active halogen (such as N-bromosuccinimide, chloramine T and chloramines B).
As the preferred oxidizing agent of the invention, are enumerated inorganic oxidizing agents including ozone, hydrogen peroxide and adducts thereof, a halogen element, and thiosulfonic acid salts; and organic oxidizing agents including quinones. It is a preferred embodiment to use the reduction sensitization in combination with the oxidizing agent to silver. Such can be achieved by a method selected from a method in which the oxidizing agent is used, and the reduction sensitization is then performed, a method in which the reduction sensitization is performed, and the oxidizing agent is then used, and a method in which the both are present together. Such a method can be carried out in the step of grain formation or in the step of chemical sensitization.
The photographic emulsion to be used in the invention can contain various compounds for the purposes of preventing the fogging or stabilizing the photographic performance during the production step, preservation or photographic processing of photographic materials. That is, many compounds that are known as an antifoggant or a stabilizer, such as thiazoles (such as benzothiazolium salts), nitroimidazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobeznzothaizoles, mercaptobenzimidazoles, mercaptothiadiazoles, aminotriazoles, benzotriazoles, nitrobenzotriazoles, mercaptotetrazoles (especially, 1-phenyl-5-mercaptotetrazole), mercaptopyrimidines, mercaptotriazines, thioketo compounds (such as oxadolinethione), and azaindenes (such as triazaindenes, tetraazaindenes (especially, 4-hydroxy-susbtituted (1,3,3a,7a)tetrazaazaindenes), and pentaazaindens), can be added. Further, compounds as described in U.S. Pat. Nos. 3,954,474 and 3,982,947 and JP-B-52-28660 can be used. Moreover, compounds as described in JP-A-63-212932 are also preferred. The antifoggant and stabilizer can be added at any timing, for example, before the grain formation, during the grain formation, after the grain formation, in the water rinsing step, during the dispersion after the water rinsing, before the chemical sensitization, during the chemical sensitization, after the chemical sensitization, or before the application, depending on the purpose. When the antifoggant and stabilizer are added during the preparation of the emulsion, not only the original antifogging effect and stabilization effect are revealed, but also various purposes such as to control the crystal habit of grain, to make the grain size small, to reduce the dissolution of grains, to control the chemical sensitization, and to control the alignment of dyes are revealed.
The silver halide emulsion as prepared by the invention can be used as any of color photographic materials and black-and-white photographic materials. Examples of the color photographic materials include color printing papers, color photographic films, color reversal films, and color diffusion transfer films; and examples of the black-and-white photographic materials include general photographic films, X-ray films, films for medical diagnosis, films for printing photosensitive material, and diffusion transfer films.
In the fields of films for medical diagnosis and films for printing photosensitive material, it is possible to carry out exposure efficiently by a laser image setter or a laser imager.
The technologies in these fields are described in JP-A-7-287337, JP-A-4-335342, JP-A-5-313289, JP-A-8-122954, and JP-A-8-292512.
Further, the silver halide emulsion of the invention can be used as a heat-developable photosensitive material. For example, there are known materials containing a photosensitive layer or layers having a catalytically effective amount of a photo catalyst (such as silver halides), a reducing agent, a reducible silver salt (such as organic silver salts), and optionally a color toner for controlling the color tone of silver, dispersed in a binder matrix. These are described in U.S. Pat. Nos. 3,152,904, 3,457,075, 2,910,377 and 4,500,626, JP-B-43-4924, JP-A-11-24200, JP-A-11-24201, JP-A-11-30832, JP-A-11-84574, JP-A-11-65021, JP-A-11-109547, JP-A-11-125880, JP-A-11-129629, JP-A-11-133536, JP-A-11-133537, JP-A-11-133538, JP-A-11-133539, JP-A-11-133542, JP-A-11-133543, JP-A-11-223898, JP-A-11-352627, JP-A-6-130607, JP-A-6-332134, JP-A-332136, JP-A-6-347970, JP-A-7-261354, and Japanese Patent Application No. 2000-89436.
The compound of the invention can be suitably used for diffusion transfer photosensitive materials. Among them, the heat-developable diffusion transfer mode can be referred to the methods as described in Japanese Patent Application Nos. 10-265273 (using a preformed dye) and 2000-89436 (using a coupling forming dye); and the instant photographic mode can be referred to the method as described in Japanese Patent Application No. 11-89801.
As to the preparation method of the photographic emulsion to be used in the invention, the description at from column 63, line 36 to column 65, line 2 of JP-A-10-239789 can be applied.
Further, as to additives such as color couplers, additives for photographic materials, kind of photosensitive materials to which the invention is applied, and processing of photosensitive materials, the description at from column 65, line 3 to column 73, line 13 of JP-A-10-239789 can be applied.
For the silver halide photographic material of the invention, are used the foregoing various additives. Besides, various additives can be used depending on the purpose.
These additives are described in detail in Research Disclosure, Item 17643 (December 1978), ibid., Item 18716 (November 1979), and ibid., Item 308119 (December 1989), and the corresponding parts are tabulated below.
The technologies such as layer alignment, which can be used for the emulsion of the invention and the photographic material using the emulsion, silver halide emulsions, dye forming couplers, functional couplers such as DIR couplers, various additives, and development processings are described in European Patent No. 0565096A1 (published Oct. 13, 1993) and the patents cited therein, and the respective items and corresponding parts are tabulated below.
The exposure method the silver halide photographic material of the invention will be described below.
The exposure for obtaining a photographic image can be carried out in a usual manner. In other words, various known light sources such as natural light (sunlight), tungsten lamps, fluorescent lamps, mercury vapor lamps, xenon arc lamps, carbon arc lamps, xenon flash lamps, laser, LED, and CRT can be used. Further, lights emitting from fluorescent materials excited by electron beams, X-rays, xcex3(gamma)-rays, or xcex1-rays can also be used for the exposure.
In the invention, a laser light source is often used preferably. Examples of the laser light include lasers using as a laser oscillation medium a helium-neon gas, an argon gas, a krypton gas, or a carbon dioxide gas; lasers using as an oscillation medium a solid such as ruby and cadmium; liquid lasers; and semiconductor lasers. The laser light is different from a usual light used for illumination and is a coherent light having uniform phases at a single frequency and a sharp directional property. Accordingly, the silver halide photographic material for achieving the exposure using such a laser light as the light source is required to have a spectral characteristic adaptive to the emission wavelength of the laser to be used.
Among the foregoing lasers, is preferable a semiconductor laser.
The compound of the invention can be used as a filter dye, an irradiation preventing dye, or an anti-halation dye for the purposes of enhancing the sharpness and color separation performance, other than the sensitizing dye.
This compound can be contained in coating solutions for the silver halide photographic material layers, filter layer, and/or anti-halation layer in the customary manner. The amount of the dye to be used is sufficiently one necessary for coloring the photographic layer, and can be properly chosen depending on the use purpose by those skilled in the art. In general, the dye is preferably used such that the optical density is in the range of from 0.05 to 3.0. The dye may be added in any step before the application.
A polymer having a charge opposite to the dye ion can be made co-present as a mordant in the layer, thereby localizing the dye in a specific layer by a mutual action with the dye molecule.
As the polymer mordant, can be enumerated those described in U.S. Pat. Nos. 2,548,564, 4,124,386, 3,625,694, 3,958,995, 4,168,976 and 3,445,231.
The compound of the invention can be added to any desired layer such as an interlayer, a protective layer, and a back layer, other than the photosensitive emulsion layers.
The compound of the invention can be used for various non-silver halide mode photo image formation method as a photo sensitizer (photo-charge separating agent) and can also be used as a photo catalyst or a photo hydrogen generator.
In the invention, the light absorption intensity means a light absorption area intensity by the sensitizing dye per unit surface area of grain and is defined as a value obtained by integrating an optical density, Log (I0/(I0xe2x88x92I)) (wherein represents a quantity of light incident to the unit surface area of grain, and I represents a quantity of light as absorbed by the sensitizing dye on the surface) by the wave number (cmxe2x88x921). The integrating range is from 5,000 cmxe2x88x921 to 35,000 cmxe2x88x921.
With respect to the silver halide photographic emulsion according to the invention, it is preferred that silver halide grains having a light absorption intensity of 100 or more in the case of grains having a spectral absorption maximum wavelength of 500 nm or more, or those having a light absorption intensity of 60 or more in the case of grains having a spectral absorption maximum wavelength of less than 500 nm, are contained in a proportion of 1/2 or more of the projected area of the whole of silver halide grains. Further, in the case of grains having a spectral absorption maximum wavelength of 500 nm or more, the light absorption intensity is preferably 150 or more, more preferably 170 or more, and most preferably 200 or more. In the case of grains having a spectral absorption maximum wavelength of less than 500 nm, the light absorption intensity of 90 or more, more preferably 100 or more, and most preferably 120 or more. In any of these cases, though the upper limit of the light absorption intensity is not defined, the light absorption intensity is preferably 2,000 or less, more preferably 1,000 or less, and most preferably 500 or less.
With respect to grains having a spectral absorption maximum wavelength of less than 500 nm, it is preferred that the spectral absorption maximum wavelength is 350 nm or more.
As one example of the method of measuring the light absorption intensity, can be enumerated a method using a microspectrophotometer. The microspectrophotometer is a device capable of measuring an absorption spectrum of a fine area and can measure a transmission spectrum of one grain. With respect to the measurement of the absorption spectrum of one grain by miscrospectrophotometry, the report of Yamashita, et al. (Pre-print of the 1996 Annual Meeting of Society of Photographic Science and Technology, Japan, page 15) can be referred to. The absorption intensity per grain is determined from this absorption spectrum. Since the light transmitting the grain is absorbed on two surfaces of an upper surface and a lower surface, the absorption intensity per unit area of the grain surface can be determined as a xc2xd value of the absorption intensity per grain, as obtained by the foregoing method. At this time, an interval where the absorption spectrum is integrated is from 5,000 cmxe2x88x921 to 35,000 cmxe2x88x921 according to the definition of the light absorption intensity. But, it may be experimentally allowed to integrate an interval containing a section of about 500 cmxe2x88x921 before and after the interval where the absorption by the sensitizing dye is present.
Further, the light absorption intensity is a value determined unequivocally by the oscillator strength of the sensitizing dye and the number of adsorbed molecules per unit area and can be calculated by determining the oscillator strength of the sensitizing dye, the adsorption amount of the dye, and the grain surface area.
The oscillator strength of the sensitizing dye can be experimentally determined as a value in proportion to the absorption area intensity of the sensitizing dye solution (optical densityxc3x97cmxe2x88x921). When the absorption area intensity per 1M of the dye is defined as A (optical densityxc3x97cmxe2x88x921), the adsorption amount of the sensitizing dye is defined as B (mole/mole-Ag), and the grain surface area is defined as C (m2/mole-Ag), the light absorption intensity can be determined according to the following equation within an error range of about 10%.
0.156xc3x97Axc3x97B/C 
Even when the light absorption intensity is calculated from this equation, a value substantially identical with the light absorption intensity as measured according to the foregoing definition (a value obtained by Log (I0/(I0xe2x88x92I)) by the wave number (cmxe2x88x921)).
As the method of increasing the light absorption intensity, there are a method of adsorbing the dye chromophore in more than one layer on the grain surface, a method of increasing the molecular absorption coefficient, and a method of decreasing the dye-occupied area, and any of these methods can be employed. Among them, is preferable the method of adsorbing the dye chromophore in more than one layer on the grain surface.
Here, the state that the dye chromophore is adsorbed in more than one layer on the grain surface means that the dye restrained in the vicinity of the silver halide grains is present in more than one layer, but the dye present in the dispersion medium is not included. The terms xe2x80x9cmore than one layerxe2x80x9d as referred to herein also include the case where as in the invention, the dye chromophore is covalently linked to the compound such as the dye adsorbed on the grain surfaces. At this time, it is required that the spectral sensitization occurs by the dye not directly adsorbed on the grain surfaces. For achieving this matter, transmission of an excitation energy from the dye not directly adsorbed on the silver halide grains to the dye directly adsorbed on the grains is required. Accordingly, in the case where the transmission of the excitation energy is required to occur over 10 stages, the ultimate transmission efficiency of the excitation energy becomes low, and hence, such is not preferred. As one example of this matter, is enumerated the case of JP-A-2-113239, i.e., a major part of the dye chromophore such as a polymer dye is present in the dispersion medium, and hence, 10 or more stages are required for the transmission of the excitation energy.
The adsorption of the dye chromophore on the silver halide grains preferably occurs in 1.5 or more layers, more preferably 1.7 or more layers, and most preferably 2 or more layers.
In the invention, the state where the chromophore is adsorbed in more than one layer on the silver halide grains means the state where when the saturated adsorption amount per unit area as attained by a dye having a smallest dye-occupied area on the silver halide grain surface among the sensitizing dyes to be added to the emulsion is defined as a one-layer saturated coverage, the adsorption amount per unit area of the dye chromophore to the one-layer saturated coverage is high. Further, the number of adsorption layers means the adsorption amount when the one-layer saturated coverage is standardized. Here, in the case of the dye to which the dye chromophore is covalently linked, the dye-occupied area of the individual dyes in the non-linked state can be standardized.
The dye-occupied area can be determined from an adsorption isotherm showing the relationship between the liberated dye density and the adsorbed dye density and a grain surface area. The adsorption isotherm can be, for example, determined with reference to A. Herz, et al., Adsorption from Aqueous Solution, Advances in Chemistry Science, No. 17, page 173 (1968).
The adsorption amount of the sensitizing dye on the emulsion grains can be determined by the following two methods: a method in which the dye-adsorbed emulsion is separated into emulsion grains and a supernatant gelatin aqueous solution by a centrifugal separator, a non-adsorbed dye density is determined by the spectral absorption measurement of the supernatant, and the adsorbed dye amount is obtained by subtracting the non-adsorbed dye density from the added dye amount; and a method in which the precipitated emulsion grains are dried, a certain amount of the precipitate is dissolved in a mixed solution (1:1) of an sodium thiosulfate aqueous solution and methanol, and the spectral absorption of the solution is measured to determine the adsorbed dye amount. In the case of using plural kinds of sensitizing dyes, the adsorption amount of the individual dyes can be determined by means such as high-performance liquid chromatography.
The dye-occupied area can be experimentally determined. Usually, since the molecule-occupied area of the sensitizing dye to be used is about 80 square-angstrom, the number of adsorption layers can be estimated while simply considering that the dye-occupied area of all dyes is 80 square-angstrom.
In the silver halide photographic emulsion containing the compound of the invention as a sensitizing dye, a distance between the shortest wavelength and the longest wavelength exhibiting 50% of each of a maximum value (Amax) of the spectral absorbance and a maximum value (Smax) of the spectral sensitivity by the sensitizing dye is preferably 120 nm or less, and more preferably 100 nm or less.
Further, a distance between the shortest wavelength and the longest wavelength exhibiting 80% of each of Amax and Smax is preferably 20 nm or more, and preferably 100 nm or less, more preferably 80 nm or less, and most preferably 50 nm or less.
Moreover, a distance between the shortest wavelength and the longest wavelength exhibiting 20% of each of Amax and Smax is preferably 180 nm or less, more preferably 150 nm or less, further preferably 120 nm or less, and most preferably 100 nm or less.
The longest wavelength exhibiting a spectral absorbance of 50% of Amax or Smax is preferably from 450 nm to 510 nm, or from 560 nm to 610 nm, or from 640 to 730 nm.
In the invention, in the case where the dye chromophore is adsorbed in plural layers on the silver halide grains, any reduction potential and oxidation potential may be employed with respect to the dye chromophore of the first layer directly adsorbing the silver halide grains and the dye chromophore of the second or et seq. layers. It is preferred from the standpoints of the promotion of electron transfer or prevention of reverse electron transfer from the dye of the second or et seq. layers to the dye of the first layer that the reduction potential of the dye chromophore of the first layer is nobler than a value obtained by subtracting 0.2 V from the value of the reduction potential of the dye chromophore of the second or et seq. layers. Preferably, the reduction potential of the dye chromophore of the first layer is nobler than the value of the reduction potential of the dye chromophore of the second or et seq. layers.
The reduction potential and oxidation potential can be measured by various methods, and preferably by phase discrimination type second harmonic alternating current polarography to determine a precise value. The measurement of potential by the phase discrimination type second harmonic alternating current polarography is described in Journal of Imaging Science, Vol. 30, page 27 (1986).
As the dye chromophore of the second or et seq. layers, luminescent dyes are preferable. As the kind of the luminescent dye, ones having a skeleton structure of a dye to be used for dye lasers are preferred. These are summarized in Mitsuo Maeda, Review of Laser Engineering, Vol. 8, pages 694, 803 and 958 (1980), ibidi., Vol. 9, page 85 (1981), and F. Sehaefer, Dye Lasers, Springer (1973).
It is preferred from the standpoint of the energy transfer efficiency from the dye of the second or et seq. layers to the dye of the first layer that the absorption maximum wavelength of the dye chromophore of the first layer in the silver halide photographic material is longer than the absorption maximum wavelength of the dye chromophore of the second or et seq. layers that the emission of the dye chromophore of the second or et seq. layers overlaps the absorption of the dye chromophore of the first layer. Further, it is preferred that the dye chromophore of the first layer forms a J-associated body. Moreover, in order to have absorption and spectral sensitivity within a desired wavelength range, it is preferred that the dye chromophore of the second or se seq. layers also forms a J-associated body.
The energy transfer efficiency of the excitation energy of the dye of the second layer to the dye of first layer is preferably 30% or more, more preferably 60% or more, and most preferably 90% or more. The excitation energy of the dye of the second layer as referred to herein means an energy that the dye in the excited state as generated upon absorption of the light energy of the dye of the second layer. In the case where the excitation energy that a certain molecule has transfers to other molecule, it is considered that the excitation energy transfers via an excitation electron transfer mechanism, a Forster model energy transfer mechanism, a Dextor model energy transfer mechanism, etc. Accordingly, in the multilayered adsorption system of the invention, it is preferred that the conditions for causing the excitation energy transfer with good efficiency that can be considered from these mechanisms be met. In addition, it is particularly preferred that the conditions for causing the Forster model energy transfer mechanism be met.
The efficiency of the energy transfer of the dye of the second layer to the dye of the first layer can be determined as a spectral sensitization efficiency at the excitation of the dye of the second layer/a spectral sensitization efficiency at the excitation of the dye of the first layer.
The meanings of the terms as used in the invention will be described below.
Dye-Occupied Area:
An occupied area per molecule of the dye, which can be experimentally determined from the adsorption isotherm. In the case of a dye to which the dye chromophore is covalently linked, the dye-occupied area of the individual dyes in the non-linked state is a standard. It is simply 80 square-angstrom.
Monolayer Saturated Coverage:
A dye adsorption amount per unit grain surface area at the application of monolayer saturation, which is an inverse of the minimum dye-occupied area of the dyes added.
Multilayer Adsorption:
A state where the adsorption amount of the dye chromophore per unit grain surface area is higher than the monolayer saturated coverage. Incidentally, since the multilayer adsorption means the state where the adsorption amount of the dye chromophore per unit grain surface area is higher than the monolayer saturated coverage, in the case where two dye chromophores are adsorbed by one layer as a dye to which they are covalently linked, they are adsorbed by two layers.
Number of Adsorption Layers:
An adsorption amount of the dye chromophore per unit grain surface area when the monolayer saturated coverage is a standard. Incidentally, in the case of a compound to which two dye chromophores are covalently linked, the xe2x80x9c(adsorption amount)xc3x972xe2x80x9d is defined as the number of adsorption layers. For example, in the case where the dye to which two dye chromophores are covalently linked is identical in the dye-occupied area and adsorption amount with a certain non-linked model dye, the number of adsorption layers is 2.